import java.util.ArrayList;

public class BicycleList 
{
    //私有静态成员变量，存储唯一实例
    private static BicycleList instance = null;
    //书籍列表
    private ArrayList<Bicycle> list = null;

     //私有构造函数
     private BicycleList() {
        this.list = new ArrayList<Bicycle>();
    }

    //公有静态成员方法，返回唯一实例
    public static BicycleList GetBicycleList() {
        if (instance == null) {
            instance = new BicycleList();
        }
        return instance;
    }

    public void display() {
        for (Bicycle bicycle : list)
            System.out.println(bicycle);
    }
}